DVB-T Signal Ambiguity Function Control for Passive Radars

The use of digital video broadcasting-terrestrial (DVB-T) signals as waveform of opportunity for passive coherent location (PCL) is addressed here. The ambiguity function (AF) of the considered waveform of opportunity has been shown to yield regularly spaced undesired peaks which might strongly limit the target detection capability of a DVB-based PCL system. A new technique for DVB-T AF control is proposed, able to overcome the limitations of previously proposed approaches in terms of achievable performance, system requirements, and computational burden. The performance analysis against simulated and real data shows that the proposed technique yields an effective removal of the undesired peaks in the AF thus making the considered waveform more attractive for PCL surveillance.

I. Introduction

It is well known that existing transmitters can be used as illuminators of opportunity for passive coherent location (PCL) [1] [2]. In particular, broadcast transmitters represent one of the most attractive choices for long range surveillance application due to their excellent coverage. The most common signals for PCL in use today are FM radio broadcast [3] as well as digital transmissions such as digital audio broadcasting (DAB) and digital video broadcasting-terrestrial (DVB-T) [4]–[5] [6] [7]. In particular, DAB and DVB-T transmissions allow a reasonable coverage and are characterized by wider bandwidth (and thus better resolution) than FM radio signals [8] [9].